logo STOP CASSINI EARTH FLYBY
Letter to the UN
- by Earl Budin, M/D., Former Assoc. Clinical Prof. of Radiology, UCLA Medical Center

The letter was sent to N. Jasentuliyana, Director, Office for Outer Space Affairs, U.N. dated 2 April 1999

Dear Sir:

This letter is to help clarify an important contradiction in the Safety Evaluation Report (SER) for the Cassini Mission by the Interagency Nuclear Safety Review Panel (INSRP) which I referred to in my letter of 12 March 1999 (#5) faxed to you 14 March and to supply you with a copy of important pages of the SER. The SER may not have been submitted to your office with the evaluation of Cassini's safety by the U.S.A. date 4 June 1997 since the SER is dated July 1997. The contradiction is the to grossly different estimates of the number of fatal cancers which may result from an accidental re-entry of the space-craft into our atmosphere during the Earth Fly-by planned by NASA for 18 August 1999: tens of thousands fatal cancers and nearly zero in the same paragraph (pages ES-4).

The estimated tens of thousands fatal cancers is based on the following facts noted in the SER:

  1. The Plutonium containers were NOT designed to withstand the heat of an accidental re-entry at the planned fly-by speed of 10 miles per second (despite NASA's claims to the contrary) - SER p. 3-24.
  2. As much as 9 kgs. Of Plutonium could be released in respirable form (particles small enough to enter the lung) - SER 3-19.
  3. "The probability of a single atom of Plutonium causing cancer" SER 3-12.

One additional very important fact was omitted from the SER (and from all of the Environmental Impact Statements by NASA) - each kilogram of Plutonium contains trillions of Plutonium atoms, thus the estimated tens of thousands fatal cancers could actually be millions of cancer deaths if the Plutonium enters a large metropolitan area such as London or New York.

A Letter to the U.S. president from INSRP (printed in the SER, inside the back cover, dated 23 September 1997) requested a 2 months delay in the launch of Cassini to enable a slower fly-by speed and thereby decrease the health risk by a factor of 30 to 100, hardly consistent with a near zero risk (the launch was not delayed!).

The estimate of near zero cancers is based on a mis-interpretation by INSRP that cancer from Plutonium results only from a certain dose of ionizing radiation received by an average person, a faulty reasoning since 1) an average person doe not exist - some will receive more, some less radiation, those who receive more being at greater risk of cancer, and 2) Plutonium causes cancer by the alpha ray emitted by each atom, and a certain radiation dose as with ordinary radiation is not required.

The planned Cassini Mission does not meet the legal Principles relevant to the safe use of nuclear power sources in outer space adopted by the U.N. 23 February 1993 on the basis of the following facts:

  1. The U.S. withheld information it had (the SER) on the safety of the nuclear power system.
  2. The Plutonium containment system does not prevent nor minimize exposure of the public to ionizing radiation.
  3. Rather than isolating the Plutonium containers, they are placed next to liquid oxygen and hydrogen containers, potential serious hazard according to former NASA scientist H. Pohler.
  4. The U.S. failed to acknowledge the special carcinogenicity of Plutonium, known to NASA which funded the most recent study demonstrating this fact.
  5. The requested increase in height of the Earth Fly-by does not significantly increase safety since the fly-by speed of 19 km per second only 20 seconds are added to the time for accidental atmospheric re-entry.
  6. The minor delay in launch date requested by the INSRP to improve safety was not accepted.

I therefore respectfully request an urgent review of the Cassini project by an independent scientific body not affiliated with the U.S., preferably prior to the 24 June 1999 start of the space craft's return toward Earth.

Earl Budin
24 Stanwood Drive
Santa Barbara, CA 93103-1534
Telephone 805-965-7327

cc. Secretary-General, U.N.
U.S. Delegation, U.N.


Posted May 9, 1999